Expandable element delivery system

ABSTRACT

Apparatus for controlling the deformation of an implant during deployment thereof, comprising: a force application mechanism for applying deformation force to the implant, by motion of a force applicator against the implant; and a restraint element positioning mechanism that positions a restraining element such that the deformation of the implant is controlled by restraint of the restraining element on allowable deformation; and a synchronizer that synchronizes the motion of the restraining element and the force applicator, to achieve a desired deformation of the implanted.

RELATED APPLICATIONS

This application is a U.S. national filing of PCT Application No.PCT/IL00/00056, filed Jan. 27, 2000. This application is also related toPCT Application Nos. PCT/IL00/00055 and PCT/IL00/00058, the disclosuresof which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to delivery systems for expandableimplants, and especially to delivery systems for a spinal prosthesis.

BACKGROUND OF THE INVENTION

A common medical situation is that of a ruptured spinal disc. Materialthat exits the disc may press against the spinal cord, causing severepain. A ruptured disc is typically treated by a surgical procedure, inwhich the damaged disc is partially or completely removed, and spinalfusion, in which at least the two vertebrae adjacent the removed discare fused.

Disk removal may be performed percutaneously, for example via a tubethrough which tissue removal devices and/or an endoscope are provided.

Several approaches exist for spinal fusion. In one approach, the twovertebrae are connected using a plate and/or screws. In anotherapproach, a spacer (also called a “cage device”) is inserted between thetwo vertebrae, so that bone growth into the space will fuse the adjacentvertebra. Typically, the axis of the spacer is perpendicular to the axisof the spine and to the plane of the body. Sometimes the spacer includesa plurality of holes, to encourage bone growth into the spacer. PCTpublication WO 98/38918, the disclosure of which is incorporated hereinby reference, describes a spacer that is inserted in a collapsedcondition and expanded to fill the inter-vertebral space. Another typeof spacer, exemplified by U.S. Pat. 5,123,926 (and others) to Pisharodi,the disclosure of which is incorporated herein by reference, functionslike a concrete anchoring screw, in that a portion of the spacer,usually a center portion-thereof, expands by a relatively small amountto engage the adjacent vertebrae.

U.S. Pat. 5,800,549, the disclosure of which is incorporated herein byreference, describes a flexible disc replacement that is inserted usinga syringe. However, this replacement does not fuse adjacent vertebrae,rather, it is designed to replace the form and function of a removedinter-vertebral disc.

One disadvantage of some of known fusion devices is that a relativelylarge entry hole in the body is required to insert the device. In some,a regular-sized surgical incision is required. In others, a minimallyinvasive laproscope-size hole is required, which is still quite large.Often, the spinal processes and/or other spinal structures are damagedby the insertion of the fusion device.

Another disadvantage of some known fusion devices is lies in a relativecomplexity of procedures for delivering the devices.

Another disadvantage of some known fusion devices is a requirement totrade/off the invasiveness of the procedure (e.g., do the spinalprocesses need to be cut or the abdomen opened) and the surface contactarea between the fusion device and the bone. Generally, if the contactsurface is small, the fusion device embeds itself in the bone and thespine slowly shrinks.

SUMMARY OF THE INVENTION

An aspect of some preferred embodiments of the invention relates to amethod of controlling the deformation of an implant. In a preferredembodiment of the invention, a force is applied to the implant while theexpansion of the implant is constrained by an element external to theimplant. The expansion force is preferably applied externally to theimplant by may be applied by the implant itself, for example if theimplant is super-elastically or elastically deformed or is formed of ashape memory material. In a preferred embodiment of the invention, theforce is an axially applied fore that axially contacts the implant,causing it to expand or extend elements radially. In a preferredembodiment of the invention, the constraint element is external to theimplant and is moved between or during application of the deformationforce, to modify the deformation behavior of the implant. In a preferredembodiment of the invention, the external constrained is retracted asthe implant is axially contracted. The axial force may be applied bypushing an element towards the implant and/or by pulling the implanttowards an element.

An aspect of some preferred embodiments of the invention relates to adevice for controlling the deformation of an implant, in which anoperator applies continuous motion to a knob or lever. and the deviceconverts the continuous motion into at least two discrete motions. In anexemplary application, one motion is for applying force to the implantfor deforming it and one motion is for moving a constraining elementthat affects the deformation of the implant under the force.

In a preferred embodiment of the invention, an alternating pin mechanismis provided for alternating the applied operator motion between adeformation force providing element and a constraint element.

In an alternative embodiment of the invention, an eccentric-wheelmechanism is provided, which wheel advances and retracts two arms, onearm which applies force to the deformation and one arm which moves theconstraining element. Preferably, the two arms alternately active theconstraining element and the deformation. In some embodiments, both armsmove in phase and in other embodiments the two arms move out of phase oreven unsynchronized with regard to cycles.

In a preferred embodiment of the invention, an apertured or nubbed plateis provided for controlling the motions. In a nubbed plate, the nubs arepreferably one way nubs, which allow an arm to engage a nub when movingin one direction and slip over the nubs when moving in the otherdirection. In an apertured plate, a spring loaded pin is preferablyprovided, for locking into an aperture when a motion is completed andfor sliding along the plate when the motion is in progress.

In a preferred embodiment of the invention, the deforming force isapplied as axially as possibly with respect to the delivery system, toprevent twisting moments.

In an alternative embodiment, a two-phase apparatus is provided. Theapparatus comprises two components, one for applying force to a spacerand one for retracting a collar that acts as a constraining element. Ineach component, an operator activates the component to apply the desiredforces or motion and at the completion of the activation, the componentlocks. The operator then activates the other component until it locks.Repeats are achieved by unlocking the components and activating themagain. In a particular implementation, the collar is advanced when forceis applied to the spacer, so that the collar maintains a same positionrelative to the proximal end of the spacer.

An aspect of some preferred embodiment of the invention relates to adevice for intra-vertebral measurement. In a preferred embodiment of theinvention, the device comprises a shaft having two wings at its end.When the wings extend, the shaft advances or retracts, the amount ofmotion of the shaft being determined by the extend of extension of thewings. Various mechanisms may be used for extending the wings. In apreferred embodiment of the invention, the wings form a parallelogram,with the shaft attached to one vertex of the parallelogram and theopposite vertex constrained form moving. Advancing the shaft, extendsthe wings. One, two or more wings may be provided, thus enablingmeasurement to one side, a planar measurement or a volume measurement.Alternatively or additionally, a plurality of concentric shafts may beprovided, each with its own set of wings. The wings of the differentshafts may be perpendicular to each other, or at any other angle, forexample parallel to each other. Possibly, the angle between the wings iscontrolled by rotating the shafts relative to each other.

In some mechanisms, the relation between shaft motion and wing extensionis not linear. In a preferred embodiment of the invention, a mechanicaldisplay is coupled to the shaft and converts the shaft motion into amore readable scale, such as a linear or quasi linear scale of wingextension.

An aspect of some preferred embodiments of the invention relates to kitsfor implant procedures, comprising two or more of a delivery system(which may be sterilized or be disposable), an implant, a collar, abolt, an access tube, a trephine, a guide wire, a vertebra puncherand/or an obturator. Preferably, the kit parts are adapted for a sizeand access direction of a spacer. In some spacers, the spacer axis whenthe spacer is expanded is not parallel to the spacer insertiondirection. This can be achieved by providing different length spike soneither side of the space. Thus, a rectangular spacer, parallel to theabdomen and back can be inserted at an oblique angle to the spine.

There is thus provided in accordance with a preferred embodiment of theinvention, apparatus for controlling the deformation of an implantduring deployment thereof, comprising:

a force application mechanism for applying deforming force to theimplant, by motion of a force applicator against the implant; and

a restraint element positioning mechanism that positions a restrainingelement such that the deformation of the implant is controlled byrestraint of the restraining element on allowable deformation; and

a synchronizer that synchronizers the motion of the restraining elementand the force applicator, to achieve a desired deformation of theimplant.

Preferably, the apparatus comprises a force input which receivescontinuous motion and couples it to the force application mechanism andto the restraint element positioning mechanism. Preferably, saidcontinuous motion is reciprocating motion. Preferably, said restraintpositioning mechanism moves said restraint element during one stroke ofsaid reciprocating motion. Preferably, said one stroke comprises aretraction of said restraint mechanism from said implant.

In a preferred embodiment of the invention, said force applicationmechanism moves said force applicator during one stroke of saidreciprocating motion. Preferably, said one stroke comprises a retractionof said force applicator from said implant. Alternatively, said onestroke comprises an advance of said force applicator towards saidimplant.

In a preferred embodiment of the invention, said force applicationmechanism comprises a selective coupler that selectively couples saidinput motion to said force applicator. Alternatively or additionally,said element positioning mechanism comprises a selective coupler thatselectively couples said input motion to said restraining element.Alternatively or additionally, said synchronized motion is repetitive,comprises a plurality of cycles of positioning said restraining elementand applying said force. Alternatively or additionally, said motion isapplied simultaneously to said restraint element positioning mechanismand to said force application mechanism.

In a preferred embodiment of the invention, said motion is appliedalternately to said restraint element positioning mechanism and to saidforce application mechanism. Preferably, the apparatus comprises analternating locking mechanism that alternately couples the motion formthe force input to the restraint element positioning mechanism and tothe force application mechanism.

In a preferred embodiment of the invention, said force input comprises amanual force input.

In a preferred embodiment of the invention, said force input comprises amotorized force input.

In a preferred embodiment of the invention, said synchronizer isintegrated with said mechanisms. Alternatively or additionally, saidsynchronizer is manual, providing an indication to an operator to switchbetween the mechanisms. Alternatively, said synchronizer is automatic,switching by itself between the mechanisms.

In a preferred embodiment of the invention, said synchronizer comprisesa pin extractor for decoupling a pin from one mechanism and coupling thepin to another mechanism. Preferably, said synchronizer comprises aspring for urging said pin towards one of said mechanisms and aninclined plane for withdrawing said pin from said one mechanism andurging said pin towards said other mechanism.

In a preferred embodiment of the invention, said synchronizer blocks themotion of one of said mechanisms when a desired motion effect of saidmechanism is. achieved. Preferably, the apparatus comprises a pin thatengages an aperture to effect said locking.

In a preferred embodiment of the invention, said restraint mechanismcomprises an unevenly surfaced element for coupling said motion to saidrestraint element.

In a preferred embodiment of the invention, said force applicationmechanism comprises an unevenly surfaced element for coupling saidmotion to said force applicator. Alternatively or additionally, saidunevenly surfaced element comprises a nubbed plate. Preferably, saidnubs are one-way nubs that allow an arm element of said mechanisms toslip over them when the arm travels in one direction relative to thenubs and engages the arm when the arm travels in the opposite relativedirection.

In a preferred embodiment of the invention, said unevenly surfacedelement comprises an apertured plate.

In a preferred embodiment of the invention, said uneven surfacecomprises even surface portions separated, by uneven surface portions, aplurality of separation distances defined by said separation of surfaceportions. Preferably, said separation distances determine thedeformation of said implant. Alternatively or additionally, saidseparation distances take into account a plastic deformation of saidimplant. Alternatively or additionally, said separation distances takeinto account an. elastic deformation of said implant. Alternatively oradditionally, wherein said separation distances take into account aspring-back of said implant.

In a preferred embodiment of the invention, said force applicator andsaid force application mechanism are substantially restricted to astraight, narrow, elongate volume, thereby reducing moments on the forceapplication mechanism. Alternatively or additionally, said forceapplicator pushes against said implant.

In a preferred embodiment of the invention, said force applicator pullsa base against a far side of said implant.

In a preferred embodiment of the invention, said force applicatorexhibits axial motion, along an axis connecting the force applicator andthe implant. Alternatively, said force applicator exhibits rotationalmotion, around an axis connecting the force applicator and the implant.Alternatively, said force applicator exhibits only axial motion, alongan axis connecting the force applicator and the implant.

In a preferred embodiment of the invention, said restraint elementexhibits axial motion, along an axis connecting the force applicator andthe implant.

In a preferred embodiment of the invention, said restraint elementexhibits rotational motion, around an axis connecting the forceapplicator and the implant. Alternatively, said force applicatorexhibits only axial motion, during times when force is applied by it tothe implant, along an axis connecting the force applicator and theimplant.

In a preferred embodiment of the invention, said force applicatorapplies at least 20 Kg to said implant. Alternatively or additionally,said force applicator applies at least 40 Kg to said implant.Alternatively or additionally, said force applicator applies at least 60Kg to said implant. Alternatively or additionally, said force applicatorapplies at least 100 Kg to said implant.

In a preferred embodiment of the invention, said restraint element andsaid force applicator are elongate elements. Preferably, said restraintelement and said force applicator are cylindrical elements.

In a preferred embodiment of the invention, said cylindrical elementsare tubes.

In a preferred embodiment of the invention, said force applicatorcomprises two concentric elements, an outer element which applies forceaway from said apparatus towards said implant and an inner counter forceelement that applies force from said implant towards said apparatus.Preferably, said inner element is mechanically coupled to said implant.Alternatively said outer element is mechanically coupled to saidimplant.

In a preferred embodiment of the invention, said motion of said forceapplicator comprises motion of only one of said concentric elementsrelative to said apparatus. Preferably, said inner element retractstowards said apparatus during said motion of said force applicator.Alternatively, said outer element advances away from said apparatusduring said motion of said force applicator.

In a preferred embodiment of the invention, said inner element isdecoupled from said implant by unscrewing it. Preferably, said innerelement extends substantially all the way through said apparatus.

In a preferred embodiment of the invention, the apparatus comprises ahandle for holding said apparatus by an operator.

In a preferred embodiment of the invention, the apparatus comprisesmeans for fixing said apparatus to said patient.

In a preferred embodiment of the invention, the apparatus comprisesmeans for fixing said apparatus to a bed on which said patient lies.

In a preferred embodiment of the invention, said synchronizer adaptssaid apparatus for deforming a particular implant from a set of sametypes of implants having different geometries.

In a preferred embodiment of the invention, said synchronizersynchronizes said force applicator to apply force to said implant aftersaid implant is completely expanded.

In a preferred embodiment of the invention, said restraint element hasan outer diameter of less than 7 mm. Alternatively or additionally, saidrestraint element has an outer diameter of less than 6 mm. Alternativelyor additionally, said restraint element has an outer diameter of lessthan 5 mm. Alternatively or additionally, said restraint element has anouter diameter of less than 4 mm.

In a preferred embodiment of the invention, said implant is a spinalimplant for fusing adjacent vertebrae. Alternatively or additionally,said implant is an axially contracting and radially expanding implant.Alternatively or additionally, said implant comprises a slotted tube,which as it contracts, radially extends a plurality of spikes andwherein said restraining element encloses said tube and prevents theextension of at least one of said spikes.

In a preferred embodiment of the invention, said implant comprises aslotted tube, to which force is applied against an end of said tube, todeform the tube. Alternatively or additionally, said implant radiallyexpands by said deforming at least by a ratio of two. Alternatively oradditionally, said implant radially expands by said deforming at leastby a ratio of four.

There is also provided in accordance with a preferred embodiment of theinvention, a method of controlling the deformation of an implant,comprising:

providing a medical implant;

positioning a restraining element relative to said implant, whichrestraining element prevents deformation of at least some of saidimplant;

applying a deformation force to said implant using at least one tube;

controlling the deformation of the implant using the restrainingelement;

moving said restraining element to a new position; and

repeating said applying, said controlling and said moving, a pluralityof times. Preferably, said deformation comprises radial expansion.Alternatively or additionally, said restraining element is inside saidimplant.

Alternatively, said restraining element is outside said implant.

In a preferred embodiment of the invention, said motion of saidrestraining element is controlled using a mechanism external to theimplant. Preferably, said external mechanism receives a continuousmotion input from an operator. Preferably, the method comprisesconverting said continuous motion into discrete motion of saidrestraining element.

Alternatively or additionally, the method comprises converting saidcontinuous motion into discrete application of force to said implant.

In a preferred embodiment of the invention, said motion and said forceapplication do not overlap in time.

In a preferred embodiment of the invention, said motion and said forceapplication do overlap in time.

There is also provided in accordance with a preferred embodiment of theinvention, a method of controlling the deformation of an implant,composing:

providing an axial implant having a plurality of spikes extendingradially thereto, arranged along the implant's axis, which implant is ina collapsed state where said spikes do not extend;

enclosing said implant with a collar that restrains the extension ofsaid spikes;

inserting said implant into a desired location;

retracting said collar to allow at least one spike to extend; and

repeating said retracting until substantially all of said spikes areextended. Preferably, said spikes extend as a result of forces storedwithin said implant. Preferably, said implant is formed of asuper-elastic material. Alternatively, said implant is formed of ashape-memory material.

In a preferred embodiment of the invention, said spikes extend as aresult of forces applied externally to said implant. Preferably, saidforces are axially applied to said implant. Preferably, the methodcomprises applying an axial force to said implant after all of saidspikes are extended.

There is also provided in accordance with a preferred embodiment of theinvention, a measurement apparatus for taking measurements inside thebody, comprising:

a hollow tube, defining at least one slot at its end;

a shaft disposed within said tube; and

at least one wing coupled to said shaft and adapted to extend throughsaid slot, wherein an extension position of said wing determines anaxial motion of said shaft in said tube,

wherein said apparatus is adapted to come in contact with body fluidsand wherein said apparatus is sterile. Preferably, said apparatus issterilizable. Alternatively or additionally, said tube comprises definesat least two slots and wherein said at least one wing comprises at leasttwo wings.

In a preferred embodiment of the invention, extension of said wingsretracts said shaft towards said wings.

In a preferred embodiment of the invention, extension of said shaft awayfrom said wings extends said wings.

In a preferred embodiment of the invention, said wings are molded from asingle piece of plastic.

In a preferred embodiment of the invention, said at least one wing,defines a parallelogram, with the shaft attached to one vertex of theparallelogram and the two neighboring vertexes of the parallelogramcomprises the extended parts of two wings.

In a preferred embodiment of the invention, the apparatus comprises adial coupled to said shaft and displaying an extension of said wings asa function of a relative displacement between said shaft and said tube.Preferably, said dial comprises a scale converter that converts anon-linear coupling of said wing motion to said shaft motion into alinear scale display.

In a preferred embodiment of the invention, the apparatus comprises anaxial position control for controlling an axial position of said tuberelative to a body.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more clearly understood from the followingdetailed description of the preferred embodiments of the invention andfrom the attached drawings, in which:

FIG. 1A shows a flat projection of an expandable spacer, in anun-expanded configuration thereof, in accordance with a preferredembodiment of the invention;

FIG. 1B shows a perspective view of the spacer of FIG. 1A;

FIG. 1C shows both an axial flat projection and a front flat projectionof the spacer of FIG. 1A, in an expanded configuration thereof;

FIG. 1D shows a perspective view of the spacer of FIG. 1A, in anexpanded configuration thereof;

FIGS. 2A-2D illustrate a process of inserting and expanding a spacer, inaccordance with a preferred embodiment of the invention;

FIGS. 3A-3F illustrate a method of providing a guide tube into anintra-vertebral space, in accordance with a preferred embodiment of theinvention;

FIGS. 4A-4F illustrate an exemplary set of tools for performing themethod of FIGS. 3A-3F,in accordance with a preferred embodiment of theinvention;

FIGS. 5A-5C illustrate an intra-vertebral measurement device, inaccordance with a preferred embodiment of the invention;

FIG. 6 illustrates a trigger and display mechanism for the measurementdevice of FIGS. 5A-5C, in accordance with a preferred embodiment of theinvention;

FIGS. 7A-7F illustrate, schematically, a method of deploying the spacerof FIGS. 1A-1D, in accordance with a preferred embodiment of theinvention;

FIGS. 8A-8D illustrate. a delivery control system for affecting theprocess shown in FIGS. 7A-7F, in accordance with a preferred embodimentof the invention;

FIGS. 9A-9B illustrate a delivery control systems utilizing analternating pin, in accordance with a preferred embodiment of theinvention;

FIGS. 10A-10B illustrate an eccentric-rotation based delivery system, inaccordance with a preferred embodiment of the invention; and

FIG. 11 illustrates an alternative eccentric-rotation based deliverysystem, in accordance with another preferred embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Basic Spacer (Cage) Description

FIG. 1A shows a flat projection of an expandable spacer 20, in anun-expanded configuration thereof, in accordance with a preferredembodiment of the invention. FIG. 1B is a perspective view of spacer 20.Spacer 20 comprises an elongate hollow object 22, such as a tube, havinga plurality of spikes 24 defined thereon (in a flattened form), eachspike being defined by a pair of slots 26. In a preferred embodiment ofthe invention, the cross-section of tube 22 is a circle, as shown in anaxial projection 36 of the spacer. In the embodiment shown in FIG. 1A,tube 22 includes alternating spike segments 28 and non-spike segments30. At one end of the tube, an end-cap 34 is preferably defined. In apreferred embodiment of the invention, end-cap 34 is hollow.Alternatively, end-cap 34 is solid, but preferably comprising a porousmaterial or including holes, to enhance bone ingrowth. Alternatively oradditionally to end-cap 34, spacer 20 is attached to the end of a tube,such that only a portion of the tube, preferably an end portion, hasslits defined therein.

FIGS. 1C-1D show spacer 20 in an expanded configuration, FIG. 1C using aflat projection (side and axial) and FIG. 1D using a perspective view.When expanded, spikes 28 extend outwards and tube 22 is axiallycompressed. Non-spike segments 30 and end-cap(s) 34 preferably do notdistort. As can be seen in the figures, a considerable expansion indiameter is achieved, for example a five fold expansion. In addition, aconsiderable axial contraction is achieved, as evidenced by comparingthe thickness of a spike 24 in FIG. 1C (38) with FIG. 1A (28).

In a preferred embodiment of the invention, spacer 20 is maintained inan expanded configuration using a bolt 42. A base 44 of bolt 42 engagesone end-cap of spacer 20 and a flared lip 46 (flared for example by anadvancing pole element after the spacer is expanded) engages end-cap 34.

Although spacer 20 has been described as including non-spike portions,it should be appreciated that in some preferred embodiments of theinvention no such non-spike portions are defined, for example, if theslits are interleaved, as shown by the example of a dotted line 35 inFIG. 1A.

In a preferred embodiment of the invention, tube slits 26 include roundholes, for example holes 32, at their ends. Preferably, these holes aredefined to reduce the propagation of stress and/or mechanical failure intube 22. Alternatively or additionally, these holes are defined toweaken the end of the slit so that when spacer 20 is axially collapsed,spikes 28 will preferentially fold out at the ends of the slits (atholes 33). Alternatively or additionally, slits 26 may include holes 33at their center (the apex of spikes 28), to encourage folding of thespike at the location of the hole.

The above is a description of a limited subset of spacers, furthervariations are defined in a PCT application filed on even date with thepresent application in the Israel receiving office and titled“Expandable Element”, attorney docket 100/01325, the disclosure of whichis incorporated herein by reference.

Basic Delivery Method

FIGS. 2A-D illustrate a process of inserting and expanding spacer 20. InFIG. 2A, a damaged disc 54 is located in an inter-vertebral space 55,between a vertebra 50 and a vertebra 52. Typically, but not necessarily,before inserting a spacer between the two vertebra, disc 54 is partiallyor completely removed. Preferably, disc 54 is removed using a minimallyinvasive technique, illustrated by a thin needle 56, for example alaproscopic approach, such as described in WO 98/38918.

In FIG. 2B, the disc has been removed and a spacer 20 is inserted intointer-vertebral space 55, in an un-expanded configuration. In apreferred embodiment of the invention, spacer 20 is mounted on- orformed at- the end of an elongate member 60. Preferably, spacer 20 isinserted via a syringe or in an “over-tube” which may be retrieved, oncethe spacer is inserted. Alternatively or additionally, spacer 20 isinserted using X-Ray guidance, to avoid damaging the spinal cord and/ornearby blood vessels.

In FIG. 2C, spacer 20 is in the process of being radially expanded (andaxially shortened). A portion 62 of spacer 20 is expanded, while aportion 64 of spacer 62 is not yet expanded.

In FIG. 2D, spacer 20 is expanded over its entire length and it fillsinter-vertebral space 55. In a preferred embodiment of the invention, afixing material, such as a bone slurry or a setting fixing compound isprovided into inter-vertebral space 55, in order to encourage fusionbetween vertebra 50 and vertebra 52. In the case of a bone slurry, bonechips or bone powder, such setting may require a week or so of bed rest.Preferably, spacer 20 is stiff enough to maintain its shape until thebone sets, so that little or no bed rest is required. Alternatively oradditionally, at least some of the required stiffness is provided by thefixing material. Possibly, the fixing material degraded after a whileand/or is a foam, to allow bone ingrowth. Alternatively or additionally,to injecting a fixing material or as part of the fixing material, growthhormones, enzymes, anti-bacterial pharmaceuticals, anti-inflammatorycompounds and/or other bio-active materials may be injected into space55, to encourage fusion and/or another desired effect.

Spacer Delivery Direction

In a preferred embodiment of the invention, the surgical approach isfrom the back of the patient. Alternatively, a lateral or aposto-lateral approach may be used. It is noted that the implantedspacer may be very narrow during implantation, so it is easier to planand execute an approach, even through the abdomen. Alternatively oradditionally, it is noted that the spacer, in some preferred embodimentsof the invention, may be made flexible along its main axis, at least inits un-expanded configuration and especially as a result of the slitsformed therein. Thus, the spacer can be provided at inter-vertebralspace 55 using a curved guide, possibly a bendable guide, such as anendoscope. Alternatively, if the spacer is formed of a shape-memorymaterial, the spacer may be cooled below the temperature at which itturns ductile, so that it can be easily bent. Alternatively oradditionally, and especially if the spacer is elastic or super-elastic,the spacer may be maintained in a curved configuration during insertionusing a curved stylet inserted through the spacer, alternatively oradditionally to using a curved outer tube.

Guide Tube Insertion And Removal of Disc-Tissue Material

In a preferred embodiment of the invention, the spacer implantationprocess is performed through a guide tube, which connectsintra-vertebral space 55 with the outside of the body. In general,provision of guide tubes to the spine is known in the art, for examplefor minimally invasive disk removal.

FIGS. 3A-3F illustrate a method of providing a sleeve 102, for use as aguide tube, into an intra-vertebral space, in accordance with apreferred embodiment of the invention.

FIG. 3A illustrates a guide wire 100 inserted into space 55. Suchinsertion is typically, but not necessarily performed using X-rayimaging guidance.

A combination sleeve-obturator is then inserted over guide wire 100,possibly requiring a small incision on the skin. A sleeve 102 preferablyhas a head 106 to which a head 112 of an obturator 110 can be fixed. Alocking mechanism 114, for example using rotationally interlockingelement, in which, for example, a half turn locks or unlocks the twoheads, is preferably provided for locking the two head together.Obturator 110 also includes an inclined tip 108, preferably situated atits proximal end to aid in forcing the device through the tissue. A bodystopper 104 is preferably provided, which can be positioned along theaxis of sleeve 102, to prevent the sleeve from advancing too far intothe body. Typically, an initial estimate for the body stop position canbe determined from the X-ray images and a more exact position can bedetermined once the sleeve is inserted, for example from fluoroscopicimages. Preferably, but not necessarily, the sleeve diameter is largeenough such that the sleeve itself cannot enter all the way into space55. Preferably, different sleeve sizes are used for different parts ofthe spine. Optionally, the sleeve size and/or geometry (e.g., barbs) issuch that once the sleeve is inserted it is fixed in place and cannot beinadvertently retracted, except by application of significant force.Alternatively, The sleeve tip may include an extending barb or anexpanding ring, to hold it in place.

FIG. 3C is a perspective view of FIG. 3B.

In FIG. 3D, obturator 110 is retracted, leaving sleeve 102 in place.

In FIG. 3E a trephine 116 is provided through sleeve 102, to perforatean annulus fibrosus capsule of space 55, using a cutting tip 118 of thetrephine. Preferably, a head 120 of trephine 116 includes a slippingmechanism 122, so that it can freely rotate on head 106, and not lock asobturator 110 does.

In FIG. 3F, both trephine 116 and guide wire 100 are retracted, leavingsleeve 102 in place.

At this point the disc material is preferably removed. Optionally, theend-plates of the vertebrae are also removed.

Optionally, a plurality of holes are formed in the end-plates and/or thevertebrae, which holes may promote bone growth. Such holes may be formedusing many tools, for example, a bent guide wire, a bent-tip trephine, arotoblator or a punching device. Preferably, a bendabletip endoscope isused, to guide the hole cutting tool to a desired location.

Exemplary Guide Set

FIGS. 4A-4F illustrate an exemplary set of tools for performing themethod of FIGS. 3A-3F.

FIG. 4A illustrates an exemplary sleeve 102, having a slot 101 formednear one end, for attaching head 106 to the sleeve. In the exemplaryembodiment shown, the inner diameter is 6 mm; the outer diameter at thehead end is 8 mm and the outer diameter at the tip end is 6.5 mm. Anexemplary length is 149 mm sleeve length, between the head and the tip.

FIG. 4B illustrates an exemplary obturator 110, having a slot 111 formednear one end, for attaching head 112 thereto. In the exemplaryembodiment shown, a bore of 1.3 mm is formed for guide wire 100, fromtip 108 to the head end of obturator 110. Optionally, about 30 mm fromtip 108, the bore widens to a 3.0 mm diameter. Tip 108 is 7.84 mm long,with a minimum tip diameter of 1.8 mm. The length of obturator 110 ispreferably 180 mm long, including a part that is inside head 112. Theouter diameter of obturator 110 is preferably 6mm or slightly less.

FIG. 4C is a perspective view of an exemplary head 106 for sleeve 102,showing a part of locking mechanism 114 that is formed in head 106. Abore of 1.3 mm is preferably formed in the head for guide wire 100.

FIG. 4D is a perspective view of an exemplary head 112 for obturator110, showing. the rest of locking mechanism 114. A bore of 1.3 mm ispreferably formed in the head for guide wire 100.

FIG. 4E illustrates a detail of a tip 118 of an exemplary trephine 116,in accordance with a preferred embodiment of the invention. In general,form, such as length, diameter, slot and bore, trephine 116 can be thesame as obturator 110. Tip 118 includes a 5 mm section that has an innerdiameter of 4.7 mm and is preferably serrated or sharpened (not shown)at its distal end, so that it can be easily rotated.

FIG. 4F illustrates a head 120 for trephine 116, also illustrating ahollow inside portion for completing free-turning mechanism 122. A boreof 1.3 mm is preferably formed in the head for guide wire 100.

Space Measurement Apparatus

FIGS. 5A-5C illustrate an exemplary intra-vertebral measurement device200, in accordance with a preferred embodiment of the invention. Device200 is preferably used to measure the distance between vertebrae 50 and52 and/or other dimensions of space 55, to better select a spacer to fitand/or for exerting control over the spacer expansion, so that itmatches the physical geometry of the patient.

In some cases, it is sufficient to make one measurement in space 55. Inothers, the measurement is repeated in several. locations in space 55.

As shown in FIG. 5A, exemplary device 200 comprises a slotted tube 202having a cap 204 and a bore. A shaft 206 is inserted into the bore oftube 202. A plurality of wings 208 are preferably connected on one endto shaft 206 and abut cap 204 at their other end, so that when shaft 206is advanced, wings 208 extend. When wings 208 meet physical opposition(such as bone), they stop extending, so the advance of shaft 206 isstopped. The amount of movement of shaft 206 can be used as anindication of the measured dimension. Shaft 206 and tube 202 arepreferably, but not necessarily flexible, so that they can be centeredby wings 208 in space 55.

Length of space 55 can be measured by detecting the extreme locationsalong the width of the space where wings 208 do not extend freely, asbeing the edges of space 55.

Width and height of space 55 can be determined by rotating device 200 toan orientation at which they extend axially to the spine and taking ameasurement. These measurements may be repeated at several points alongspace 55, by axially retracting and advancing tube 202. In someembodiments, tube 202 is bent or bendable, so that non-axialmeasurements can be taken.

In the exemplary embodiment shown, the outer diameter of tube 202 is 4.8mm and wings 208 can extend to a maximum diameter of 18 mm. However, inother implementations, other sizes may be provided. For example, ifdevice 200 is used for measurement of intramedullar channels, a smallerdiameter device may be provided, for example having a diameter of 3 or 2mm. A larger range of radii may also be required, for example, between 2and 40 mm. Alternatively, a smaller range of radii may be provided, forexample between 4 and 8 mm.

FIG. 5B shows device 200 (with shaft 206 hidden) with wings 208 closed.

FIG. 5C shows device 200 (with shaft 206 hidden) with wings open. Wings208 are preferably attached to a head 210, which head may molded ontoshaft 206. Shaft 206 is preferably metal, while head 210 and wings 208are preferably a single piece of plastic. Alternatively, shaft 206 maybe plastic, possibly a single unit with wings 208.

In the exemplary embodiment shown, wings 208 form a parallelogram or adiamond, such that compressing an axial (of the shaft) axis of theparallelogram increases the other (transaxial of the shaft) axis,thereby extending wings 208. When the shaft is retracted, for exampleusing a spring, the transaxial axis is decreased, so the wings retract.In some embodiments, the spring-back of wings 208 themselves is used forretracting the wings. In an alternative embodiment, the shaft comprisesat its end a cone, which, when retracted, pushes the wings out of theslots. Many other alternate mechanisms may be used.

Trigger and Display Mechanism

FIG. 6 illustrates a trigger and display mechanism 220 for themeasurement device of FIGS. 5A-5C. Mechanism 220 comprises a trigger 222attached to an axis 234. One end 228 of trigger 222 can serve as a dialindicator 228 for indicating a position on dial 230. An optional dialextension 232 may be provided. A spring 224 coupled to a base 226 andtrigger 222 is preferably provided to return trigger 222 to a restingposition and to retract shaft 206.

A bent arm 242 interconnects tube 202, shaft 202 (at point 244) andtrigger 222, (using a pin 236). Pin 236 is free to slide in a slot 240in the body (not shown) of the measurement system) and a slot 238 oftrigger 222. This mechanism provides both spring back of the shaft andconverts the motion of the shaft into a scale that linearly shows thewing extension.

Other conversion mechanisms, such as using non-linear gears andeccentrically moving gears, may be used instead.

An axial stopper 246 is preferably provided to control the axialposition of the measurement system relative to the patient, allowingmeasurements in different parts of space 55. Other mechanisms, such as ascrew-connection to sleeve 102 may also be used.

In a preferred embodiment of the invention, system 200 is held with onehand, freeing the other hand to do other operations.

General Spacer Expansion Control

FIGS. 7A-7C illustrate an exemplary method of spacer expansion, inaccordance with a preferred embodiment of the invention. A spacer 402 isprovided as a tube having an inner bolt 408, which bolt is preferablyconfigured to prevent the advance of the end of spacer 402, past the endof the bolt. An outer collar 404 is provided for shaping the expansionof the spacer. A laproscopy tube 406 is also shown. In this embodiment,both bolt 408 and tube 406 are fixed to a base 410 outside the body.This base may be, for example, fixed to the patient and/or his bed or itmay be prevented from advancing towards the body by other means. Thus,the base of the spacer does not advance into the body. In otherembodiments described below, the bolt may be retracted, requiring thebase 410 to advance or to move relative to bolt 408, if the spacer is tomaintain its place in the body during expansion.

FIG. 7A shows a starting position, with bolt 408 and spacer 402 (in itsunexpanded state) extending between two vertebrae (not shown).

Both spacer 402 and collar 404 are advanced. However, as the spacer isprevented from advancing by bolt 408, it expands, at the areas whereexpansion is not prevented by collar 404, forming one or more spikes412. This result is shown in FIG. 7B.

Collar 404 is then retracted (FIG. 7C), so that both the collar and thespacer can be advanced again.

In some embodiments, the spike size is different for different spikes,requiring a different amount of motion for expanding each spike.Different amounts of motions can be required for other reasons as well,for example to allow better control over the spike expansion. In somecases, the spacer exhibits a spring-back effect, in that the spikes,after being extended, spring back and axially extend the spacer. Theamounts of motion preferably take the spring-back, as well as theplastic deformation, into account. In FIG. 7D, collar 404 and spacer 402are advanced by a different amount than in FIG. 7A, to create a secondspike 414.

In FIG. 7E, collar 404 is retracted by a different amount from FIG. 7B,allowing a third spike 416 to expand out (FIG. 7F).

Deployment System

FIGS. 8A-11 show several devices suitable for expanding a spacer in wayssimilar to that shown in FIGS. 7A-7F. These devices may also be used forcontrolled deployment of other implants in the body, where the relativepositions and/or orientations of several elements are modified to effector allow a certain deformation of an implant.

In the following devices, linear motion of the spacer, bolt and/orcollar is provided. However, in some embodiments, rotational motion,alternatively or additionally to linear motion, may be acceptable ordesirable. For example, spiral motion of collar 404 is generallyacceptable. Rotational motion of spacer 402 is generally not acceptable,however, a slip-ring may be provided between a pusher tube that exhibitsa spiral motion and a spacer that does not. In some embodiments, collar404 is not rotationally symmetric, for example including slits forexpansion of spikes therethrough, in which case rotational control ofthe collar angle may be advantageous.

Also, although discrete motion of the elements is generally preferred,in some embodiments, simultaneous, continuous motion of elements (suchas a bolt and a collar), even during spike expansion, are provided.

In the embodiments below, collar 404 is outside of spacer 402. However,collar 404 can be inside spacer 402, if it engages the inside of thespacer and prevent expansion at the engaged areas, for example using athreading.

Manual Deployment Device Embodiment

FIGS. 8A-8D illustrate a delivery control system 500 for effecting theprocess shown in FIGS. 7A-7F, in accordance with a preferred embodimentof the invention.

In general, system 500 includes two sub-systems, a collar retractionsubsystem and a spacer advancement sub-system. Bolt 408 is fixed to ahandle 502 of system 500.

Each of the subsystems includes a knob for effecting the motion, meansfor converting rotational motion of the knob into linear motion of themoved element and a lock for stopping the motion once the requiredextent of motion, for a particular spike expansion, has be performed. Ina preferred embodiment of the invention, the lock comprises a platehaving a plurality of holes formed in it and a pin, which slides alongthe plate and is elastically urged into a hole. The distance between theholes corresponds to the amount of motion desired in each expansionstep.

In operation, a user advances collar 404 and spacer 402 using the spaceradvancing subsystem, until a pin fits in a spacer location plate(corresponding to FIGS. 7A-7B). Then, the user retracts collar 404 usingthe collar retraction subsystem, until a pin fits in a collar locationplate (corresponding to FIGS. 7B-7C). The user then frees the pin fromthe spacer location plate and advances the spacer and collar again(corresponding to FIGS. 7C-7D). Then the user frees the pin from thecollar location plate and retracts the collar (corresponding to FIGS.7D-7E). This process is repeated until the spacer is properly deployed.A pole element that holds bolt 408 is released from the bolt and system500 is retracted. In an exemplary embodiment, the pole is threaded onthe bolt, so system 500 is rotated around its axis to free the bolt.Preferably, a screw fixing system 500 to its handle 502 is released,allowing easier rotation of system 500 and/or of the pole element. Insome embodiments, the spacer is locked to the bolt by advancing thepole-element by screwing it in tighter.

In a preferred embodiment of the invention, at the end of the spacerexpansion, an optional additional spacer advancing step is performed, tocompensate for the spring-back of the spacer and allow the cap-lockingmechanism of the spacer to be deployed.

Although a particular implementation of the above described device isshown, other implementations may be provided instead, while maintainingthe general scheme of operation described above.

FIG. 8A is a side perspective view of device 500, showing a knob 504that is part of the spacer advancement subsystem. Spacer location plate506 can be seen in side profile. A button 508 for freeing the pin (notshown in this figure) from spacer location plate 506. A button 510 freesthe rest of system 500 to rotate relative to handle 502. As the spaceradvancement generally requires great force, knob 504 preferably includesa significant lever and/or gear-reduction. Preferably, button 510 isused after the spacer is locked to its bolt and/or the pole-element hasbeen at least partly unscrewed, however, this is not essential.

A knob 512 is provided as part of the collar retraction subsystem. Agear 516, rotated by knob 514, engages a linear gear 518. A collarlocation plate 520 can be seen on edge. A pin locking mechanism 522,will be described below. A button 514 on knob 512 is used to releasemechanism 522 and the pin from collar location plate 520.

FIG. 8B is a perspective view of system 500 from its other side, showinglocking mechanism 522 and collar location plate 520 in greater detail.In particular, a plurality of holes 530 in collar location plate 520 areshown.

Spacer advancement is achieved by the rotation of knob 504 advancing afree-turning (or counter-threaded) bolt (not shown in this figure)having a plurality of pins 528 extending trans-axially from it. Thesepins are engaged by slots 526 in a tube 524, restricting the bolt (andthe spacer advancing system) to linear motion.

FIG. 8C is a cut-through view of FIG. 8B, showing spacer location plate506 in greater detail, especially a plurality of holes 532 for anelastically biased pin 534 to engage, when the pin is adjacent one ofthe holes.

Knob 504 turns a threaded axis 536, having mounted on it afree-rotating, threaded or a counter threaded bolt 538 (from which pin528 extends).

A pole element 540, that engages bolt 408 (not shown) is fixed in placerelative to handle 502. A spacer pushing rod 542 is only affected by themotion of linear gear 518. A collar 404 is advanced by the motion oflinear gear 518 and retracted by the motion of a collar retractionassembly 544 coupled to gear 516.

A solution for unthreading pole element 540 from bolt 408, alternativeto using button 510 (FIG. 8A) is to extend pole element 540 throughthreaded axis 536, until knob 504. A button (not shown) may be providedto couple the rotation of knob 504 to element 540 or a separate knob maybe provided. Thus, when deployment of the spacer is completed, poleelement 540 can be easily rotated. This solution may also be applied tothe other embodiments described below.

FIG. 8D illustrates the locking mechanism for the collar motion ingreater detail. A pin 554 is urged by a spring 550 in knob 512 to engagecollar location plate 520 (not shown). A rod 552 couples release button514 and locking mechanism 522, to retract pin 554 from the collarlocation plate, when needed.

Alternating Pin Embodiment

FIGS. 9A-9B illustrate a delivery control system 600, utilizing analternating pin, in accordance with a preferred embodiment of theinvention.

Unlike system 500 of FIGS. 8A-8D, system 600 uses a continuousrotational motion of a gear 606 to retract a linear gear 604 andcomponents attached to it (described below) through an opening 608 in ahandle 602 of system 600.

Another difference from system 500 is that in system 600, asimplemented, spacer 402 is not advanced, instead, both bolt 408 andcollar 404 are retracted.

FIG. 9B shows in detail an alternating pin mechanism for selectivelyretracting with linear gear 604 either collar.404 or bolt 408.

Pole element 540, which retracts bolt 408 is fixed to a bolt-retractor610. A pin 612 is provided to prevent rotation of retractor 610 and/orprevent un-powered axial motion of retractor 610.

A plurality of holes 614 are formed in retractor 610 for receiving a pin618. When pin 618 is in one of holes 614, linear gear 604 is coupled toretractor 610, by pin 618, so that backwards motion of gear 604 causesretraction of bolt 408. Pin 618 is urged towards retractor 610 by aspring 620. However, a plurality of inclined planes 621, which arepreferably fixed relative to handle 602, meet pin 618 as it movesbackwards with linear gear 604 and urge pin 618 away from bolt retractor610, to a collar retractor 622. Also collar retractor 622 preferably hasa plurality of holes 624 formed in it for engaging pin 618. Collarretractor 622 is preferably coupled to collar 404, so that linear motionof gear 604 retracts collar 404. As collar retractor 622 and pin 618move backwards with linear gear 604, pin 608 moves closer to a hole 614,which, once reached, engages pin 618 and decouples collar retractor 622from linear gear 604.

Pull-Pull Embodiment

FIGS. 10A-10B illustrate an eccentric-rotation based delivery system700, in accordance with a preferred embodiment of the invention.

In this embodiment, a knob 702 is used to rotate a wheel 704 (thereference number points to a covering of the wheel, as the rim of thewheel is hidden). Forward motion of the two arms are attached to thewheel, at off-axis positions, such that turning wheel 704 advances onearm and retracts the other arm, for one half of its rotation andretracts the one arm and advances the other arm on its other half ofrotation. One arm is a bolt retraction arm 706 and the other arm is acollar retraction arm 708. Each of the arm, when it retracts engages anubbed bar that is coupled to either collar 404 or bolt 408. When thearms advance, they slip forward, over one or more nubs to the next nubfor retraction.

Collar retraction arm 708 engages a nubbed bar 710, having a pluralityof one-way nubs 712 formed thereon. Nubs 712 are flat on one side, toengage a flat aperture formed (or protrusion) in arm 708. The nubs areinclined at their other side, to allow an inclined surface of arm 708 toslip over them, when the arm advances.

A similar mechanism is provided for arm 706 and its associated bar 714and nubs 716.

It is noted that in this and other embodiments, the distance between thenubs (or aperture sin other embodiments) is selected to achieve adesired amount of motion of the collar and/or bolt. Thus, also theretraction motion of the arms may include some slippage of the armagainst the bar, rather than retraction. The off-axis assistance betweenthe arm and the wheel axis, can also be used to control the forceleveraging and the amount of retraction possible.

In the figures, the bolt, spacer and sleeve are shown extending directlyfrom device 700, however, in some embodiment, a pole element is used forretracting the bolt and/or a spacer pusher is used for coupling thespacer to device 700. In device 700 as shown, the spacer does not moverelative to device 700, so device 700 advances as the spacer axiallycontracts.

Although arms 706 and 708 are shown to be 180° apart from each other, insome embodiment, a different angular difference is used, so that thereis an overlap in their advancing and/or retracting motions.

Push-Pull Embodiment

FIG. 11 illustrates an alternative eccentric-rotation based deliverysystem 800, in accordance with another preferred embodiment of theinvention.

System 800 illustrates two features desirable in some preferredembodiments of the invention:

-   -   (a) advancing spacer 402 while maintaining bolt 408 in place;        and    -   (b) reduction of moments in the forces applied to spacer 402.

These two features are substantially independent and one may be providedwithout the other.

As will be seen from FIG. 11 and the following description, forces onspacer 402, which are generally the highest forces applied during spacerdeployment, are applied substantially axially, so that there is littleor no twisting and/or bending moment. In some cases, forces of 30, 60 oreven 100 Kg may be applied to the spacer, to expand it.

Like system 700 of FIGS. 10A and 10B, eccentric motion of a wheel isused to alternate advancing and retraction of arms. However, unlikesystem 700, in system 800, one arm is active while advancing and theother while retracting.

A knob 802 is used to rotate a wheel 804 and a wheel 806. In someembodiments, these wheels include a gear reduction mechanism forreducing motion while increasing force.

Wheel 806 is coupled to an arm 808 which engages a nubbed bar 810 whenit retracts, thereby retracting collar 404. As in system 700, when arm808 advances, it can slip over one or more one-way nubs 812. It shouldbe noted that arm 808 is preferably near the axis of device 800.

Wheel 804 is coupled to an arm 814 which is, in turn, coupled to acylinder 816 that is centered on the axis of device 800. A nub engagingtip 818 is coupled to cylinder 816, preferably using a leaf spring 824,so that it can engage a nub 822 of a nubbed bar 820, when it advances.When arm 814 retracts, also tip 818 retracts and slips over the one-waynubs, as in system 700.

Although FIG. 11 does not show a sheath. System 800 is preferablysheathed using a cylindrical sheath.

Spacer Removal

Although the spacers are generally permanently implanted, it issometimes desirable to remove them. In a preferred embodiment of theinvention, the same devices used for implanting the spacers are used forretrieving them, being activated backwards (the collar advancing and thespacer retracting or the bolt advancing). Using dedicated devices isuseful for controlling the direction in which the spacer will axiallygrow and to ensure that the uncollapsed spikes do not scratch thesurrounding tissue. In some cases, it is necessary to unlock the boltfrom the spacer end, for example by cutting or by bending in a flange ofthe bolt.

Delivery System Fixation

In a preferred embodiment of the invention, the delivery system ishand-held, being fixed in two dimensions by a laproscopic tube used toaccess space 55. The delivery system may also be fixed to the tube toprevent axial motion and/or rotation. Generally, it is desirable thatthe system needs to be held with at most one hand (or no hands), leavinga second hand for performing various activities. In some cases, the freehand is used to rotate the knows used to expand the spacer.

In some embodiments, the body of the delivery system is fixed to thepatient's body (possibly via a framework) and/or to the bed on which thepatient lies. Many fixing methods can be used, for example the deliverysystem being clamped to the bed. Alternatively, other fixing methods,for example as used in neurological procedures, may be used.

In some embodiments, the operator's hand is not mechanically coupled tothe delivery system, for example the delivery system being controlledusing a flexible tube or wire or using wireless means.

In any of the above embodiments, power for expanding the spacer may beprovided by a motor, rather than from the operator. however, in manycases it is desirable to provide feedback, especially tactile feedback,to the operator regarding the expansion of the spacer. In a preferredembodiment of the invention, non-tactile feedback is provided by asensor that measures the relative motion of the bolt and the spacer or asensor that measures the forces applied top the spacer. In a preferredembodiment of the invention, if the forces exceed a threshold, do notmatch the motion and/or do not match an expected force pattern or if themotion is unusual, an alert is provided, for example an audio alert.

Location Control

In the embodiments described above, a rigid tube is used to control thetrans-axial and/or axial location of the delivery system and the spacerand a body stopper is used to limit the axial motion of the spacer.However, in some embodiments, such control may not be suitable orsufficient. In a preferred embodiment of the invention, the implantationof tubes uses x-ray imaging or other external medical imaging techniquesto prevent damage to nerves, blood vessels and other adjacent tissue.Alternatively, visual imaging, such as using an endoscope, is used.Alternatively or additionally, ultrasonic imaging is used. Alternativelyor additionally, local MRI imaging, for example using a local coil(possibly inside the body) is used. Such imaging tool may be providedthrough the access tube and through the delivery system, beside thedelivery system or instead of the delivery system. In some cases, asecond tube with the imaging tool is provided. Alternatively oradditionally, a position sensor may be coupled to the tools and using areference coupled to the body, a position of the tool and/or proximityto various body structures can be determined. Such a display is known inthe art and can be overlaid on a two or three dimensional image of thebody.

A position sensor or an ultrasonic imager may be integrated with thebolt of the spacer. Alternatively, such a bolt is hollow or is notneeded. Space 55 is generally free, so a simple ultrasonic distancesensor may be used to detect if a tool is nearing dangerous areas.Possibly, a Doppler signal is used to detect the proximity of bloodvessels. Such a Doppler signal can be time gated.

Alternatively, a fixed framework to which all tools are coupled is used.The allowed motion of the tools relative to the framework can be fixedmechanically or a sensor can detect the motion and generate a signal ifan allowed ball park is exceeded.

Although the above described sleeve 102 can serve as such a framework,it is useful if the delivery system is coupled to the sleeve end insidethe body and that sleeve 102 can be fixed in place in the body, forexample using an expanding tip or a barbed tip. In one embodiment, thecollar is threaded to sleeve 102 and retracted by rotation of thecollar. Alternatively or additionally, the delivery system may be sofixed to sleeve 102. Alternatively or additionally, a tool that couplesthe end of the spacer to sleeve 102 is provided to limit or sense motionof the end of the spacer. As the spacer is not solid, this limiting toolcan remain in the body while the spacer is being expanded.

The use of an internal reference is especially useful if one or more ofthe tools is bent or flexible.

Non-Axial Variations

As described above, the various tools are generally rigid and straight.However, in some embodiments of the invention, bent tools, such as tubesand delivery systems, may be used. Alternatively or additionally,flexible tools, tubes and delivery systems may be used.

It is noted that although the above described devices are preferablyapplied inside the body, at least for testing and training purposes,these devices may also be used to expand an implant outside of a livinghuman body, for example in the air, in a model, in an animal or inside acadaver.

It will be appreciated that the above described apparatus and methodsfor delivering expandable inserts may be varied in many ways. Inaddition, a multiplicity of various features, both of methods and ofdevices have been described. It should be appreciated that differentfeatures may be combined in different ways. In particular, not all thefeatures shown above in a particular embodiment are necessary in everysimilar preferred embodiment of the invention. Further, combinations ofthe above features are also considered to be within the scope of somepreferred embodiments of the invention. It should also be appreciatedthat many of the embodiments are described only as methods or only asapparatus, however the scope of the invention includes both methods forusing apparatus and apparatus for applying the methods. The scope of theinvention also covers machines for creating the apparatus describedherein. In addition, the scope of the invention includes methods ofusing, constructing, calibrating and/or maintaining the apparatusdescribed herein. Section headings where they appear are meant forclarity and ease of browsing the application and are not to be construedas limiting the applicability of subject matter described within. Whenused in the following claims or in the text above, the terms“comprises”, “comprising”, “includes”, “including” or the like mean“including but not limited to”.

1. Apparatus for controlling the deformation of an implant duringdeployment thereof, comprising: a force application mechanism forapplying deforming force to the implant, by axial motion of a forceapplicator against the implant; and a restraint element positioningmechanism that positions a restraining element such that the deformationof the implant is controlled by restraint of the restraining element onallowable deformation; and a synchronizer that synchronizers the motionof the restraining element and the force applicator, to achieve adesired deformation of the implant.
 2. Apparatus according to claim 1,comprising a force input which receives continuous motion and couples itto the force application mechanism and to the restraint elementpositioning mechanism.
 3. Apparatus according to claim 2, wherein saidcontinuous motion is reciprocating motion.
 4. Apparatus according toclaim 3, wherein said restraint positioning mechanism moves saidrestraint element during one stroke of said reciprocating motion. 5.Apparatus according to claim 4, wherein said one stroke comprises aretraction of said restraint mechanism from said implant.
 6. Apparatusaccording to claim 3, wherein said force application mechanism movessaid force applicator during one stroke of said reciprocating motion. 7.Apparatus according to claim 6, wherein said one stroke comprises aretraction of said force applicator from said implant.
 8. Apparatusaccording to claim 6, wherein said one stroke comprises an advance ofsaid force applicator towards said implant.
 9. Apparatus according toclaim 2, wherein said force application mechanism comprises a selectivecoupler that selectively couples said input motion to said forceapplicator.
 10. Apparatus according to claim 2, wherein said elementpositioning mechanism comprises a selective coupler that selectivelycouples said input motion to said restraining element.
 11. Apparatusaccording to claim 2, wherein said synchronized motion is repetitive,comprises a plurality of cycles of positioning said restraining elementand applying said force.
 12. Apparatus according to claim 2, whereinsaid motion is applied simultaneously to said restraint elementpositioning mechanism and to said force application mechanism. 13.Apparatus according to claim 2, wherein said motion is appliedalternately to said restraint element positioning mechanism and to saidforce application mechanism.
 14. Apparatus according to claim 13,comprising an alternating locking mechanism that alternately couples themotion form the force input to the restraint element positioningmechanism and to the force application mechanism.
 15. Apparatusaccording to claim 2, wherein said force input comprises a manual forceinput.
 16. Apparatus according to claim 2, wherein said force inputcomprises a motorized force input.
 17. Apparatus according to claim 1,wherein said synchronizer is integrated with said mechanisms. 18.Apparatus according to claim 1, wherein said synchronizer is manual,providing an indication to an operator to switch between the mechanisms.19. Apparatus according to claim 1, wherein said synchronizer isautomatic, switching by itself between the mechanisms.
 20. Apparatusaccording to claim 1, wherein said synchronizer comprises a pinextractor for decoupling a pin from one mechanism and coupling the pinto another mechanism.
 21. Apparatus according to claim 20, wherein saidsynchronizer comprises a spring for urging said pin towards one of saidmechanisms and an inclined plane for withdrawing said pin from said onemechanism and urging said pin towards said other mechanism. 22.Apparatus according to claim 1, wherein said synchronizer blocks themotion of one of said mechanisms when a desired motion effect of saidmechanism is achieved.
 23. Apparatus according to claim 22, comprising apin that engages an aperture to effect said locking.
 24. Apparatusaccording to claim 1, wherein said restraint mechanism comprises anunevenly surfaced element for coupling said motion to said restraintelement.
 25. Apparatus according to claim 1, wherein said forceapplication mechanism comprises an unevenly surfaced element forcoupling said motion to said force applicator.
 26. Apparatus accordingto claim 24, wherein said unevenly surfaced element comprises a nubbedplate.
 27. Apparatus according to claim 26, wherein said nubs areone-way nubs that allow an arm element of said mechanisms to slip overthem when the arm travels in one direction relative to the nubs andengages the arm when the arm travels in the opposite relative direction.28. Apparatus according to claim 24, wherein said unevenly surfacedelement comprises an apertured plate.
 29. Apparatus according to claim24, wherein said uneven surface comprises even surface portionsseparated, by uneven surface portions, a plurality of separationdistances defined by said separation of surface portions.
 30. Apparatusaccording to claim 29, wherein said separation distances determine thedeformation of said implant.
 31. Apparatus according to claim 29,wherein said separation distances take into account a plasticdeformation of said implant.
 32. Apparatus according to claim 29,wherein said separation distances take into account an elasticdeformation of said implant.
 33. Apparatus according to claim 29,wherein said separation distances take into account a spring-back ofsaid implant.
 34. Apparatus according to claim 1, wherein said forceapplicator and said force application mechanism are substantiallyrestricted to a straight, narrow, elongate volume, thereby reducingmoments on the force application mechanism.
 35. Apparatus according toclaim 1, wherein said force applicator pushes against said implant. 36.Apparatus according to claim 1, wherein said force applicator pulls abase against a far side of said implant.
 37. Apparatus according toclaim 1, wherein said force applicator exhibits axial motion, along anaxis connecting the force applicator and the implant.
 38. Apparatusaccording to claim 1, wherein said force applicator exhibits rotationalmotion, around an axis connecting the force applicator and the implant.39. Apparatus according to claim 37, wherein said force applicatorexhibits only axial motion, along an axis connecting the forceapplicator a nd the implant.
 40. Apparatus according to claim 1, whereinsaid restraint element exhibits axial motion, along an axis connectingthe force applicator and the implant.
 41. Apparatus according to claim1, wherein said restraint element exhibits rotational motion, around anaxis connecting the force applicator and the implant.
 42. Apparatusaccording to claim 40, wherein said force applicator exhibits only axialmotion, during times when force is applied by it to the implant, alongan axis connecting the force applicator and the implant.
 43. Apparatusaccording to claim 1, wherein said force applicator applies at least 20Kg to said implant.
 44. Apparatus according to claim 1, wherein saidforce applicator applies at least 40 Kg to said implant.
 45. Apparatusaccording to claim 1, wherein said force applicator applies at least 60Kg to said implant.
 46. Apparatus according to claim 1, wherein saidforce applicator applies at least 100 Kg to said implant.
 47. Apparatusaccording to claim 1, wherein said restraint element and said forceapplicator are elongate elements.
 48. Apparatus according to claim 47,wherein said restraint element and said force applicator are cylindricalelements.
 49. Apparatus according to claim 47, wherein said cylindricalelements are tubes.
 50. Apparatus according to claim 1, wherein saidforce applicator comprises two concentric elements, an outer elementwhich applies force away from said apparatus towards said implant and aninner counter force element that applies force from said implant towardssaid apparatus.
 51. Apparatus according to claim 50, wherein said innerelement is mechanically coupled to said implant.
 52. Apparatus accordingto claim 50, wherein said outer element is mechanically coupled to saidimplant.
 53. Apparatus according to claim 50, wherein said motion ofsaid force applicator comprises motion of only one of said concentricelements relative to said apparatus.
 54. Apparatus according to claim53, wherein said inner element retracts towards said apparatus duringsaid motion of said force applicator.
 55. Apparatus according to claim53, wherein said outer element advances away from said apparatus duringsaid motion of said force applicator.
 56. Apparatus according to claim50, wherein said inner element is decoupled from said implant byunscrewing it.
 57. Apparatus according to claim 56, wherein said innerelement extends substantially all the way through said apparatus. 58.Apparatus according to claim 1, comprising a handle for holding saidapparatus by an operator.
 59. Apparatus according to claim 1, comprisingmeans for fixing said apparatus to said patient.
 60. Apparatus accordingto claim 1, comprising means for fixing said apparatus to a bed on whichsaid patient lies.
 61. Apparatus according to claim 1, wherein saidsynchronizer adapts said apparatus for deforming a particular implantfrom a set of same types of implants having different geometries. 62.Apparatus according to claim 1, wherein said synchronizer synchronizessaid force applicator to apply force to said implant after said implantis completely expanded.
 63. Apparatus according to claim 1 wherein saidrestraint element has an outer diameter of less than 7 mm.
 64. Apparatusaccording to claim 1 wherein said restraint element has an outerdiameter of less than 6 mm.
 65. Apparatus according to claim 1 whereinsaid restraint element has an outer diameter of less than 5 mm. 66.Apparatus according to claim 1 wherein said restraint element has anouter diameter of less than 4 mm.
 67. Apparatus according to claim 1,wherein said implant is a spinal implant for fusing adjacent vertebrae.68. Apparatus according to claim 1, wherein said implant is an axiallycontracting and radially expanding implant.
 69. Apparatus according toclaim 1, wherein said implant comprises a slotted tube, which as itcontracts, radially extends a plurality of spikes and wherein saidrestraining element encloses said tube and prevents the extension of atleast one of said spikes.
 70. Apparatus according to claim 1, whereinsaid implant comprises a slotted tube, to which force is applied againstan end of said tube, to deform the tube.
 71. Apparatus according toclaim 1, wherein said implant radially expands by said deforming atleast by a ratio of two.
 72. Apparatus according to claim 1 wherein saidimplant radially expands by said deforming at least by a ratio of four.73. A method of controlling the deformation of an implant, comprising:providing a medical implant; positioning a restraining element relativeto said implant, which restraining element prevents deformation of atleast some of said implant; applying a deformation force to said implantusing at least one tube; controlling the deformation of the implantusing the restraining element; moving said restraining element to a newposition; and repeating said applying, said controlling and said moving,a plurality of times, such that in each repetition a different portionof the implant is prevented from deforming by the restraining element.74. A method according to claim 73, wherein said deformation comprisesradial expansion.
 75. A method according to claim 73, wherein saidrestraining element is inside said implant.
 76. A method according toclaim 73, wherein said restraining element is outside said implant. 77.A method according to claim 73, wherein said motion of said restrainingelement is controlled using a mechanism external to the implant.
 78. Amethod according to claim 77, wherein said external mechanism receives acontinuous motion input from an operator.
 79. A method according toclaim 78, comprising converting said continuous motion into discretemotion of said restraining element.
 80. A method according to claim 78,comprising converting said continuous motion into discrete applicationof force to said implant.
 81. A method according to claim 73, whereinsaid motion and said force application do not overlap in time.
 82. Amethod according to claim 73, wherein said motion and said forceapplication do overlap in time.
 83. A method of controlling thedeformation of an implant, composing: providing an axial implant havinga plurality of spikes extending radially thereto, arranged along theimplant's axis, which implant is in a collapsed state where said spikesdo not extend; enclosing said implant with a collar that restrains theextension of said spikes; inserting said implant into a desiredlocation; retracting said collar to allow at least one spike to extend;and repeating said retracting until substantially all of said spikes areextended.
 84. A method according to claim 83, wherein said spikes extendas a result of forces stored within said implant.
 85. A method accordingto claim 84, wherein said implant is formed of a super-elastic material.86. A method according to claim 84, wherein said implant is formed of ashape-memory material.
 87. A method according to claim 83, wherein saidspikes extend as a result of forces applied externally to said implant.88. A method according to claim 87, wherein said forces are axiallyapplied to said implant.
 89. A method according to claim 88, comprisingapplying an axial force to said implant after all of said spikes areextended.
 90. Apparatus for controlling the deformation of a tube havinga slotted section, comprising: a force application mechanism forapplying deforming force to the slotted section, by axial motion of aforce applicator against the slotted section; a restraint elementpositioning mechanism that positions a restraining element such that thedeformation of the slotted section is controlled by restraint of therestraining element on allowable deformation; and a synchronizer thatsynchronizers the motion of the restraining element and the forceapplicator, to achieve a desired deformation of the slotted section. 91.An apparatus according to claim 90, wherein said slotted section isformed of plastic.
 92. Apparatus according to claim 90, comprising aforce input which receives continuous motion and couples it to the forceapplication mechanism and to the restraint element positioningmechanism.
 93. Apparatus according to claim 92, wherein said continiousmotion is reciprocating motion.
 94. Apparatus according to claim 93,wherein said restraint positioning mechanism moves said restraintelement during one stroke of said reciprocating motion.
 95. Apparatusaccording to claim 94, wherein said one stroke comprises a retraction ofsaid restraint mechanism from said slotted section.
 96. Apparatusaccording to claim 93, wherein said force application mechanism movessaid force applicator during one stroke of said reciprocating motion.97. Appratus according to claim 96, wherein said one stroke comprises arefraction of said force applicator from said slotted section. 98.Apparatus according to claim 96, wherein said one stroke comprises anadvance of said force applicator towards said slolled section. 99.Apparatus according to claim 92, wherein said force applicationmechanism comprises a selective coupler that selectively couples saidinput motion to said force applicator.
 100. Apparatus according to claim92, wherein said element positioning mechanism comprises a selectivecoupler that selectively couples said input motion to said restrainingelement.
 101. Apparatus according to claim 92, wherein said synchronizedmotion is repetitive and comprises a plurality of cycles of positioningsaid restraining element and applying said force.
 102. Apparatusaccording to claim 92, wherein said motion is applied simultaneously tosaid restraint element positioning mechanism and to said forceapplication mechanism.
 103. Apparatus according to claim 92, whereinsaid motion is applied alternately to said restraint element positioningmechanism and to said force application mechanism.
 104. Apparatusaccording to claim 103, comprising an alternating locking mechanism thatalternately couples the motion from the force input to the restraintelement positioning mechanism and to the force application mechanism.105. Apparatus according to claim 92, wherein said force input comprisesa manual force input.
 106. Apparatus according to claim 92, wherein saidforce input comprises a motorized force input.
 107. Apparatus accordingto claim 90, wherein said synchronizer is integrated with saidmechanisms.
 108. Apparatus according to claim 90, wherein saidsynchronizer is manual, providing an indication to an operator to switchbetween the mechanisms.
 109. Apparatus according to claim 90, whereinsaid synchronizer is automatic, switching by itself between themechanisms.
 110. Apparatus according to claim 90, wherein saidsynchronizer comprises a pin extractor for decoupling a pm from onemechanism and coupling the pin to another mechanism.
 111. Apparatusaccording to claim 110, wherein said synchronizer comprises a spring forurging said pin towards one of said mechanisms and an inclined plane forwithdrawing said pin from said one mechanism and urging said pin towardssaid other mechanism.
 112. Apparatus according to claim 90, wherein saidsynchronizer blocks the motion of one of said mechanisms when a desiredmotion effect of said mechanism is achieved.
 113. Apparatus according toclaim 112, comprising a pin that engages an aperture to effect saidlocking.
 114. Apparatus according to claim 90, wherein said restraintmechanism comprises an unevenly surfaced element for coupling saidmotion to said restraint element.
 115. Appratus according to claim 90,wherein said force application mechanism comprises an unevenly surfacedelement for coupling said motion to said force applicator. 116.Apparatus according to claim 114, wherein said unevenly surfaced elementcomprises a nubbed plate.
 117. Apparatus according to claim 116, whereinsaid nubs are one-way nubs that allow an arm element of said mechanismsto slip over them when the arm travels in one direction relative to thenubs and engages the arm when the aim travels in the opposite relativedirection.
 118. Apparatus according to claim 114, wherein said unevenlysurfaced element comprises an apertured plate.
 119. Apparatus accordingto claim 114, wherein said uneven surface comprises even surfaceportions separated, by uneven surface portions, a plurality ofseparation distances defined by said separation of surface portions.120. Apparatus according to claim 119, wherein said separation distancesdetermine the deformation of said slotted section.
 121. Appratusaccording to claim 119, wherein said separation distances take intoaccount a plastic deformation of said slotted section.
 122. Apparatusaccording to claim 119, wherein said separation distances take intoaccount an elastic deformation of said slotted section.
 123. Apparatusaccording to claim 119, wherein said separation distances take intoaccount a spring-back of said slotted section.
 124. Apparatus accordingto claim 90, wherein said force applicator and said force applicationmechanism are substantially restricted to a straight, narrow, elongatevolume, thereby reducing moments on the force application mechanism.125. Apparatus according to claim 90, wherein said force applicatorpushes against said slotted section.
 126. Apparatus according to claim90, wherein said force applicator pulls a base against a far side ofsaid slotted section.
 127. Apparatus according to claim 90, wherein saidforce applicator exhibits axial motion, along an axis connecting theforce applicator and the slotted section.
 128. Apparatus according toclaim 90, wherein said force applicator exhibits rotational motion,around an axis connecting the force applicator and the slotted section.129. Apparatud according to claim 127, wherein said force applicatorexhibits only axial motion, along an axis connecting the forceapplicator and the slotted section.
 130. Apparatus according to claim90, wherein said restraint element exhibits axial motion, along an axisconnecting the force applicator and the slotted section.
 131. Apparatusaccording to claim 90, wherein said restraint element exhibitsrotational motion, around an axis connecting the force applicator andthe slotted section.
 132. Apparatus according to claim 130, wherein saidforce applicator exhibits only axial motion, during times when force isapplied by it to the slotted section, along an axis connecting the forceapplicator and the slotted section.
 133. Apparatus according to claim90, wherein said force applicator applies at least 20 Kg to said slottedsection.
 134. Apparatus according to claim 90, wherein said forceapplicator applies at least 40 Kg to said slotted section. 135.Apparatus according to claim 90, wherein said force applicator appliesat least 60 Kg to said slotted section.
 136. Apparatus according toclaim 90, wherein said force applicator applies at least 100 Kg to saidslotted section.
 137. Apparatus according to claim 90, wherein saidrestraint element and said force applicator are elongate elements. 138.Apparatus according to claim 137, wherein said restraint element andsaid force applicator are cylindrical elements.
 139. Apparatus accordingto claim 137, wherein said cylindrical elements are tubes. 140.Apparatus according to claim 90, wherein said force applicator comprisestwo concentric elements, an outer element which applies force away fromsaid apparatus towards said slotted section and an inner counter forceelement that applies force from said slotted section towards saidapparatus.
 141. Apparatus according to claim 140, wherein said innerelement is mechanically coupled to said slotted section.
 142. Apparatusaccording to claim 140, wherein said outer element is mechanicallycoupled to said slotted section.
 143. Apparatus according to claim 140,wherein said motion of said force applicator comprises motion of onlyone of said concentric elements relative to said apparatus. 144.Apparatus according to claim 143, wherein said inner element retractstowards during said motion of said force applicator.
 145. Apparatusaccording to claim 143, wherein said outer element advances away fromsaid apparatus during said motion of said force applicator. 146.Apparatus according to claim 140, wherein said inner element extendssubstantially all the way through said apparatus.
 147. Apparatusaccording to claim 90, comprising a handle for holding said apparatus byan operator.
 148. Apparatus according to claim 90, comprising means forfixing said apparatus to said patient.
 149. Apparatus according to claim90, comprising means for fixing said apparatus to a bed on which saidpatient lies.
 150. Apparatus according to claim 90, wherein saidsynchronizer synchronizes said force applicator to apply force to saidslotted section after said slotted section is completely expanded. 151.Apparatus according to claim 90 wherein said restraint element has anouter diameter of less than 7 mm.
 152. Apparatus according to claim 90wherein said restraint element has an outer diameter of less than 6 mm.153. Apparatus according to claim 90 wherein said restraint element hasan outer diameter of less than 5 mm.
 154. Apparatus according to claim90 wherein said restraint element has an outer diameter of less than 4mm.
 155. Apparatus according to claim 90 wherein said slotted sectionradially expands by said deforming at least by a ratio of two. 156.Apparatus according to claim 90 wherein said slotted section radiallyexpands by said deforrning at least by a ratio of four.
 157. Apparatusaccording to claim 147, wherein said apparatus is configured that adistal end of said slotted section does not move relative to said handleduring said applying.
 158. Apparatus according to claim 58, wherein saidapparatus is configured so that a distal end of said implant does notmove relative to said handle during said applying.
 159. Apparatusaccording to claim 90, wherein said slotted section is configured toexpand to have a uniform radial diameter.
 160. Apparatus according toclaim 90, wherein said slotted section is configured to expand to have aradial diameter which varies along the tube axis.
 161. Apparatusaccording to claim 90, wherein said slotted section comprises an endportion of an unslotted tube.
 162. A method of controlling thedeformation of a slotted tube, comprising: providing an axial tubehaving at least a slotted end such that said slots are configured toexpand as a plurality of spikes extending radially thereto, said spikesarranged along the tube axis, which slotted end is in a collapsed statewhere said spikes do not extend; enclosing said slotted end with acollar that restrains the extension of said spikes; inserting said tubeinto solid tissue; retracting said collar relative to said slotted endto allow at least one spike to extend in said solid tissue; andrepeating said retracting until substantially all of said spikes areextended.
 163. A method according to claim 162, wherein said slottedtube is formed of plastic.